Comparison of the short-term effects of facemask therapy preceded by conventional rapid maxillary expansion or by an alternate rapid maxillary expansions and constrictions protocol : Aretrospective study.

Abstract

We aimed to compare the short-term effects of alternate rapid maxillary expansion and constriction (Alt-RAMEC) with conventional rapid maxillary expansion (RME) followed by facemask (FM) therapy. A total of 30patients who had received facemask therapy after RME or Alt-RAMEC protocols were included in the study. The Alt-RAMEC/FM and RME/FM groups were created to be well-matched regarding cervical vertebral maturation stage and sex. In the Alt-RAMEC group (10males and 5females, 10.99 ± 1.80years), expansion screws were activated for aweek (two turns/day), then deactivated in the following week (two turns/day). The activation-deactivation protocol continued for 6 or 7weeks. In the RME/FM group (10males and 5females, 11.61 ± 1.20years), screw activation was performed according to the patients' requirements. Lateral cephalograms which had been taken at the beginning of treatment and at the end of the facemask therapy were analyzed. Intragroup and intergroup differences were statistically analyzed. Both groups showed asignificant sagittal advancement of the maxilla. However, the Alt-RAMEC/FM group showed statistically greater improvements than the RME/FM group for SNA (3.11 ± 1.79 vs. 1.45 ± 1.34, p = 0.008), ANB (4.29 ± 1.80 vs. 2.95 ± 1.19, p = 0.023), convexity (8.91 ± 4.29 vs. 5.61 ± 2.51, p = 0.016), and overjet (5.86 ± 2.29 vs. 4.61 ± 2.10, p < 0.001). The sagittal mandibular, vertical skeletal, dental, and soft tissue changes were similar between the groups (p > 0.05). The Alt-RAMEC protocol was found to be more effective in the correction of skeletal classIII malocclusion in the short term.